As the plant matures it will begin to use up and shed the fan leaves, causing them to turn yellow starting from the bottom so this is normal. Some people pull them, and some don't and let them fall. Personally, I pull mine to keep the girls looking cared for. Some say the plant uses up stored energy from the leaves, and if you pull them they don't get all the value of the leaves.
Also, it's my opinion not to stress about when to begin flushing, and you can begin anytime you decide to. Sure, there may be a small difference in overall yield if you were to stop feeding a couple of weeks early but not an appreciable difference.
You mentioned being in it for the long run, so you are still patient... Cool. This can be an anxious time for the new or novice grower, or those of us who have not grown is years but not much longer in the big picture. I have to say though that once you have brought a plant to maturity you will know what to look for and expect.
Also, as for looking at the trich's I use a pair of binoculars, and look through them backwards which allows you to get right up close and see a magnified view.